Design of the On-line Fission Gas Release Analysis System in the High Flux Reactor Petten

Within the European High Temperature Reactor Technology Network (HTR-TN) and related projects a number of HTR fuel irradiations are planned in the High Flux Reactor Petten (HFR) with the objective to explore the potential of recently produced fuel for even higher temperature and burnup. For these irradiation tests a specific installation was designed and installed, dubbed the ¿Sweep Loop Facility (SLF)¿. The SLF is tasked with three functions, namely temperature control, surveillance of safety parameters and analysis of fission gas release for three individual capsules in two separate experiments. This paper describes the gas activity measurement technique and shows how qualitative and quantitative analysis of volatile fission products can be performed on-line. The fractional release of these fission products, defined as the ratio between release rate of a gaseous fission isotope (measured) to its instantaneous birth rate (calculated), is a licensing-relevant experimental result of HTR fuel irradiation experiments, because it determines the operational (as opposed to accidental) source term for radioactivity release. The newly developed data acquisition system allows for higher measurement frequencies if activity values increase, thus enabling follow-up of transients. The SLF is designed to deal with a wide range of activities by modification of the distance between detectors and gas samples.

LAURIE Mathias;  MARMIER Alain;  BERG Gerardus;  FUETTERER Michael; 

2009-01-27

IAEA

JRC42260

https://publications.jrc.ec.europa.eu/repository/handle/JRC42260,